Development of an upper-body robotic rehabilitation platform that furthers motor recovery after neuromuscular injuries

This dissertation presents the development of an upper-body exoskeleton and its control framework for robotic rehabilitation of the arm and shoulder after a neurological disorder such as a stroke. The first step is designing an exoskeleton hardware that supports natural mobility of the human upper body with a wide range of motion for enabling most rehabilitation exercises. The exoskeleton is equipped with torque-controllable actuation units for implementing various robotic rehabilitation protocols based on force and impedance behaviors. The control framework is designed to exhibit a highly backdrivable behavior with a gravity compensation for the robot's weight and optional gravity support for user's arm weight to promote voluntary movements of patients with motor impairments. The control framework also serves as a `substrate' of other robotic control behaviors for rehabilitation exercises by superimposing desired force or impedance profiles. A stability analysis is performed to examine the coupled stability between the robot and human. After designing the hardware and control, several experiments are carried out to test the mobility and dynamic behavior of the robot. Lastly, a human subject study evaluates the effectiveness of the robot's shoulder mechanism and control algorithm in assisting the coordination around the shoulder. The results show that the robot induces desirable coordination in the presence of abnormalities at the shoulder.Mechanical Engineerin

Arabidopsis BAG1 Functions as a Cofactor in Hsc70-Mediated Proteasomal Degradation of Unimported Plastid Proteins

1143Ysciescopu

Continuous preparation of bicelles using hydrodynamic focusing method for bicelle to vesicle transition

Bicelle is one of the most stable phospholipid assemblies, which has tremendous applications in the research areas for drug delivery or structural studies of membrane proteins owing to its bio-membrane mimicking characteristics and high thermal stability. However, the conventional preparation method for bicelle demands complicated manufacturing processes and a long time so that the continuous synthesis method of bicelle using microfluidic chip has been playing an important role to expand its feasibility. We verified the general availability of hydrodynamic focusing method with microfluidic chip for bicelle synthesis using various kinds of lipids which have a phase transition temperature ranged from − 2 to 41°C. Bicelle can be formed only when the inside temperature of microfluidic chip was over the phase transition temperature. Moreover, the concentration condition for bicelle formation varied depending on the lipids. Furthermore, the transition process characteristics from bicelle to vesicle were analyzed by effective q-value, mixing time and dilution condition. We verified that the size of transition vesicles was controlled according to the effective q-value, mixing time, and temperature.RDA (PJ01574703), NRF (2020K2A9A2A08000174), NK226E, MAFRA (118105–3

Electrochemical Studies for Cation Recognition with Diazo-Coupled Calix[4]arenes

The electrochemical properties of diazophenylcalix[4]arenes bearing ortho-carboxyl group (o-CAC) and ortho-ester group (o-EAC), respectively, in the presence of various metal ions were investigated by voltammetry in CH3CN. o-CAC and o-EAC showed voltammetric changes toward divalent metal ions and no significant changes with monovalent alkali metal ions. However, o-CAC preferentially binds with alkaline earth and transition metal ions, whereas no significant changes in voltammetric signals are observed in o-EAC with alkaline earth metal ions. o-EAC only binds with other transition metal ions. This can be explained on metal ion complexation-induced release of proton from the azophenol to the quinone-hydrazone tautomer followed by internal complexation of the metal ion with aid of nitrogen atoms and ortho-carbonyl groups in the diazophenylazocalix[4]arenes

Theiler's Virus Infection Induces a Predominant Pathogenic CD4+ T Cell Response to RNA Polymerase in Susceptible SJL/J Mice▿

Theiler's murine encephalomyelitis virus (TMEV)-induced immune-mediated demyelinating disease in susceptible mouse strains has been extensively investigated as a relevant model for human multiple sclerosis. Previous investigations of antiviral T-cell responses focus on immune responses to viral capsid proteins, while virtually nothing is reported on immune responses to nonstructural proteins. In this study, we have identified noncapsid regions recognized by CD4+ T cells from TMEV-infected mice using an overlapping peptide library. Interestingly, a greater number of CD4+ T cells recognizing an epitope (3D21-36) of the 3D viral RNA polymerase, in contrast to capsid epitopes, were detected in the CNS of TMEV-infected SJL mice, whereas only a minor population of CD4+ T cells from infected C57BL/6 mice recognized this region. The effects of preimmunization and tolerization with these epitopes on the development of demyelinating disease indicated that capsid-specific CD4+ T cells are protective during the early stages of viral infection, whereas 3D21-36-specific CD4+ T cells exacerbate disease development. Therefore, protective versus pathogenic CD4+ T-cell responses directed to TMEV appear to be epitope dependent, and the differences in CD4+ T-cell responses to these epitopes between susceptible and resistant mice may play an important role in the resistance or susceptibility to virally induced demyelinating disease

Development of a Concurrent Treatment Technique of Ethyl Formate and Mixtures (Nitrogen, Phosphine) to Control Citrus Mealybug (<i>Planococcus citri</i>)

Currently, the fumigant ethyl formate (EF) is stored as a liquified gas in metal cylinders mixed with carbon dioxide (CO2), but this product type is expensive to manufacture, transport, and maintain in cylinders. To address these problems, we developed a new EF fumigation technique with a nitrogen (N2) carrier. In this report, the susceptibility of citrus mealybugs, one of the most resistant mealybugs to fumigants, to EF was assessed; the phytotoxicity of an EF + N2 concurrent treatment applied to banana fruit was examined to evaluate the efficacy compared to the current EF + CO2 product; and the increased efficacy with a phosphine (PH3) addition to EF + N2 was also assessed. Concurrent treatment of EF and N2 was performed at an LC50 concentration of EF. N2 was applied in seven doses from concentrations of 79% to 95%. The phytotoxicity of EF to bananas was assessed by applying EF at 35 mg/L with N2 at 79%, and the color, sugar content, and weight loss of bananas were measured for 14 days after treatment. The EF with N2 treatment resulted in more than 50% mortality at all growth stages of the mealybug, and there was no significant difference between the untreated and treated banana fruits. EF mixed with PH3 showed a higher efficacy than treatment with EF alone, but only a slight increase in efficacy was observed when the PH3 concentration increased. These results indicate that concurrent treatment with EF and N2 can be used to control mealybugs on banana fruits, and combined treatment with EF and PH3 can also enhance the efficacy against mealybugs

Enhanced Arsenic (III and V) Removal in Anoxic Environments by Hierarchically Structured Citrate/FeCO3 Nanocomposites

Novel citrate/FeCO3 nanocomposites (CF-NCs) were synthesized for effective arsenic (III and V) sorption with constant addition of Fe2+ into HCO3&minus; solution in the presence of citrate. This paper is the first report on the formation of CF-NCs, and in this study we investigate the mechanisms of arsenic uptake by the sorbent under anoxic conditions through various solid- and liquid-phase spectroscopic methods, including X-ray absorption spectroscopy. In CF-NCs, citrate was found to be incorporated into the structure of siderite (up to 17.94%) through (Fe2+citrate)&minus; complexes. The crystal morphology of rhombohedral siderite was changed into hierarchically nanostructured spherical aggregates composed of several sheet-like crystals, which improved the surface reactivity in the presence of sufficient citrate. Compared to pure siderite (15.2%), enhanced removal of As(III) in the range of 19.3% to 88.2% was observed, depending on the amount of incorporated citrate. The maximum sorption capacities of CF-NCs for As(III) and As(V) were 188.97 and 290.22 mg/g, respectively, which are much higher than those of previously reported siderite-based adsorbents. It was found that arsenic (III and V) sorption on CF-NCs occurred via bidentate corner-sharing surface complexation, predominantly without changes in the arsenic oxidation states. These results suggest that arsenic (III and V) can be attenuated by siderite in anoxic environments, and this attenuation can be even more effective when siderite is modified by incorporation of organic compounds such as citrate